Square Bar C45E
C45E is a simple engineering steel which contains about 0.45% of carbon. The relatively high carbon content renders the steel suitable for induction hardening and quenching plus tempering (Q+T). However, the low alloying level precludes good response to Q+T in larger dimensions.
C45E is standardised in SS-EN ISO 683 - 1. The (discontinued) SS-designation is 1672. Tibnor has chosen to stock bars of material with designation C45R, the only difference to C45E being a controlled level of sulphur for improved machinability. The edge-length tolerance for hot-rolled squares is as prescribed in SS-EN 10059. Height-of-arc straightness for regular straightened bars is better than 0.004 times bar length.
In tensile testing of C45E squares, the lowest permitted level for yield strength is 310 - 280 MPa depending on edge length. The interval for tensile strength is 590 - 740 MPa and for hardness 165 - 220 HB independent of dimension.
Welding of C45E is possible but anything other than very small parts should be preheated. Machinability is very good and short chips mean that the material is suitable for processing in unmanned operation.
If the application so requires, C45E is eminently suitable for induction hardening and can also be surface hardened by nitriding. A Q+T-operation can be used to increase the strength level but the hardenability is not very good so quenching is best performed using water or polymer quenchant.